17 Language support library [language.support]

17.12 Coroutines [support.coroutine]

17.12.4 No-op coroutines [coroutine.noop]

17.12.4.3 Function noop_­coroutine [coroutine.noop.coroutine]

noop_coroutine_handle noop_coroutine() noexcept;
Returns: A handle to a coroutine that has no observable effects when resumed or destroyed.
Remarks: A handle returned from noop_­coroutine may or may not compare equal to a handle returned from another invocation of noop_­coroutine.